Not infrequently, gas turbine engines present some unusual sealing requirements. Like any other apparatus having relatively moving parts, provision must be made for lubricating the interfaces of the relatively moving parts. At the same time, by reason of the incorporation of rotary compressors in gas turbine engines, there also exists high pressure gas, typically air, during operation of the turbine engine. Depending upon rotor construction, there may be an opportunity for leakage of the gas under pressure from the compressor section of the engine to the areas of power takeoffs or the like, whereat bearings are located and to which lubricant must be directed. Obviously, gas under pressure, in some situations could interfere with, or even prevent the flow of lubricant against the leaking gas under pressure to areas requiring lubrication; and care must be taken in providing seals to prevent such an occurrence.
Further, the same paths of compressed gas leakage during engine operation can also provide paths for the leakage of lubricant when the engine is not in operation.
The present invention is directed to overcoming one or more of the above problems.